Biology subjects

Yu, L.-H.

Publications and source records attributed to Yu, L.-H..

5 recordsLinked to original sources

bioRxiv2020

Rice NIN-LIKE PROTEIN 1 Rapidly Responds to Nitrogen Deficiency and Improves Yield and Nitrogen Use Efficiency

Nitrogen (N) is indispensable for crop growth and yield, but excessive agricultural application of nitrogenous fertilizers has generated severe environmental problems. A desirable and economical solution to cope with these issues is to improve crop nitrogen use efficiency (NUE). Plant NUE has been a focal point of intensive research worldwide, yet much more has to be learned about its genetic determinants and regulation. Here, we show that rice NIN-LIKE PROTEIN 1 (OsNLP1) plays a fundamental role in N utilization. OsNLP1 protein localizes in nucleus and its transcript level is rapidly induced by N starvation. Overexpression of OsNLP1 improves plant growth, grain yield and NUE under different N conditions while knockout of OsNLP1 impairs grain yield and NUE under N limiting conditions. OsNLP1 regulates nitrate and ammonium utilization by cooperatively orchestrating multiple N uptake and assimilation genes. Chromatin immunoprecipitation and yeast-one-hybrid assays show that OsNLP1 can directly bind to the promoter of these genes to activate their expression. Therefore, our results demonstrate that OsNLP1 is a key regulator of N utilization and represents a potential target for improving NUE and yield in rice. One-sentence summaryOsNLP1 rapidly responds to N availability, enhances N uptake and assimilation, and holds great potential in promoting high yield in rice.

plant biology↗

bioRxiv2020

Rice NIN-LIKE PROTEIN 4 is a master regulator of nitrogen use efficiency

Nitrogen (N) is one of the key essential macronutrients that affects rice growth and yield. Inorganic N fertilizers are excessively used to boost yield and generate serious collateral environmental pollution. Therefore, improving crop N use efficiency (NUE) is highly desirable and has been a major endeavor in crop improvement. However, only a few regulators have been identified that can be used to improve NUE in rice to date. Here we show that the NIN-like protein OsNLP4 significantly improves the rice NUE and yield. Field trials consistently showed that loss-of-OsNLP4 dramatically reduced yield and NUE compared with wild type under different N regimes. In contrast, the OsNLP4 overexpression lines remarkably increased yield by 30% and NUE by 47% under moderate N level compared with wild type. Transcriptomic analyses revealed that OsNLP4 orchestrates the expression of a majority of known N uptake, assimilation and signaling genes by directly binding to the nitrate-responsive cis-element in their promoters to regulate their expression. Moreover, overexpression of OsNLP4 can recover the phenotype of Arabidopsis nlp7 mutant and enhance its biomass. Our results demonstrate that OsNLP4 is a master regulator of NUE in rice and sheds light on crop NUE improvement.

plant biology↗

bioRxiv2019

ARABIDOPSIS NITRATE REGULATED 1 acts as a negative modulator of seed germination by activating ABI3 expression

Seed germination is a crucial transition point in plant life and is tightly regulated by environmental conditions through the coordination of two phytohormones, gibberellin and abscisic acid (ABA). To avoid unfavorable conditions, plants have evolved safeguard mechanisms for seed germination. Here, we report a novel function of the Arabidopsis MADS-box transcription factor ARABIDOPSIS NITRATE REGULATED 1 (ANR1) in seed germination. ANR1 knockout mutant is insensitive to ABA, salt, and osmotic stress during the seed germination and early seedling development stages, whereas ANR1-overexpressing lines are hypersensitive. ANR1 is responsive to ABA and abiotic stresses and upregulates the expression of ABI3 to suppress seed germination. ANR1 and ABI3 have similar expression pattern during seed germination. Genetically, ABI3 acts downstream of ANR1. Chromatin immunoprecipitation and yeast-one-hybrid assays showed that ANR1 could bind to the ABI3 promoter to regulate its expression. In addition, ANR1 acts synergistically with AGL21 to suppress seed germination in response to ABA as evidenced by anr1 agl21 double mutant. Taken together, our results demonstrate that the ANR1 plays an important role in regulating seed germination and early post-germination growth. ANR1 and AGL21 together constitutes a safeguard mechanism for seed germination to avoid unfavorable conditions.

plant biology↗

bioRxiv2018

Arabidopsis HB52 mediates the crosstalk between ethylene and auxin signaling pathways by regulating PIN2, WAG1, and WAG2 during primary root elongation

The gaseous hormone ethylene participates in many physiological processes of plants. It is well known that ethylene-inhibited root elongation involves basipetal auxin delivery requiring PIN2. However, the molecular mechanism how ethylene regulates PIN2 is not well understood. Here, we report that the ethylene-responsive HD-Zip gene HB52 is involved in ethylene-mediated inhibition of primary root elongation. Using biochemical and genetic analyses, we demonstrated that HB52 is ethylene-responsive and acts immediately downstream of EIN3. HB52 knock-down mutants are insensitive to ethylene in primary root elongation while the overexpression lines have dramatically shortened roots like ethylene treated plants. Moreover, HB52 upregulates PIN2, WAG1, and WAG2 by directly binding to their promoter, leading to an enhanced basipetal auxin delivery to the elongation zone and thus inhibiting root growth. Our work uncovers HB52 as an important crosstalk node between ethylene signaling and auxin transport in root elongation.

plant biology↗

bioRxiv2016

Arabidopsis MADS-box transcription factor AGL21 acts as environmental surveillance for seed germination by regulating ABI5

Seed germination is a crucial checkpoint for plant survival under unfavorable environmental conditions. Abscisic acid (ABA) and its signaling play a vital role in integrating environmental information to regulate seed germination. MCM1/AGAMOUS/DEFICIENS/SRF (MADS)-box transcription factors are mainly known as key regulators of seed and flower development in Arabidopsis. However, their functions in seed germination are still poorly understood. Here we report that MADS-box transcription factor AGL21 negatively modulates seed germination and post-germination growth by controlling the expression of ABA-INSENSITIVE 5 (ABI5) in Arabidopsis. AGL21 responds to multiple environmental stresses and plant hormones. The AGL21-overexpressing plants are hypersensitive to ABA, salt and osmotic stresses during seed germination and early post-germination growth, whereas agl21 mutants are less sensitive. AGL21 positively regulates ABI5 expression in seeds. Genetic analyses reveal that AGL21 is epistatic to ABI5 in controlling seed germination. Chromatin immunoprecipitation assays further demonstrate that AGL21 could directly bind to the ABI5 promoter in plant cells. Taken together, our results suggest that AGL21 acts as a surveillance integrator that incorporates environmental cues and endogenous hormonal signals into ABA signaling to regulate seed germination and early post-germination growth.

plant biology↗